1. Field of the Invention
This invention is related generally to document holders, and in particular to document holders that are adapted for in-line installation and use in combination with a keyboard and video display monitor in a data entry or word processing workstation.
2. Description of the Related Art
An important consideration in the use of computer workstations is the provision of ergonomically correct support for documents which are being viewed by the operator attending the workstation. Document holders have been developed which may be placed to one side of a keyboard and video display monitor. These holders require the operator to constantly look to the left or right to view documents supported by the holder while transferring information from the document to the computer or when comparing information on the document with information displayed on a display screen. Such motion can lead to eye strain and fatigue because of the repeated head and eye movements required for viewing the document, the display monitor and the keyboard.
The long hours of work spent by operators of data entry and word processing equipment underscores the need for a document holder which may be used safely and effectively, considering the physical constraints imposed by computer equipment and workstation furniture, and the personal limitations and preferences of operators who use the equipment. Preferably, the document holder should be positioned in-line between the keyboard and the display monitor, be adjustable toward or away from the operator, be capable of being tilted to improve line of sight and reduce glare or light reflection, be adjustable from side-to-side, and be vertically adjustable, both up and down.
Various types of document holders have been developed for use in conjunction with keyboard workstations. See, for example, U.S. Pat. No. 5,104,086; U.S. Pat. No. 5,651,524; and U.S. Pat. No. 7,100,883 which describe document holders having a generally vertically disposed easel which is adjustable vertically as well as laterally from side-to-side.
Other document holders have been developed which are supported for pivotal movement with respect to a support adjacent one side of a keyboard and associated machine, including a video monitor. These conventional document holders require frequent head movement and eye movement between positions for viewing a video display monitor and for viewing a document supported by the holder.
Document holders have also been developed for mounting at an elevated position above the work surface. However, such holders are generally not suitable for use where a video display monitor takes up a considerable amount of space directly behind the keyboard, for example in desk top computer workstations. Moreover, as mentioned above, conventional document holders have not provided the capability for precise positioning of the document easel over a wide range of viewing positions. That capability is desirable for an ergonomically correct workstation where a source document is being viewed by a keyboard operator who also requires constant reference to the video display screen. Such a range of positions should provide for correctly placing the source document to minimize head and eye movement of the operator, and more importantly, accommodate the needs of individual operators who have different physical limitations and personal viewing preferences.